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authorscf <scf@FreeBSD.org>2007-07-20 23:30:13 +0000
committerscf <scf@FreeBSD.org>2007-07-20 23:30:13 +0000
commit8db32e8a1ed746af220e5b0a1e06c8e3843893f0 (patch)
treeed5502bc3249ddd22e1a4f358ebad5cf82011ec5
parent192b9573601035404375d85939b0e5cfd098f7a8 (diff)
downloadFreeBSD-src-8db32e8a1ed746af220e5b0a1e06c8e3843893f0.zip
FreeBSD-src-8db32e8a1ed746af220e5b0a1e06c8e3843893f0.tar.gz
Added environ-replacement detection. For programs that "clean" (i.e., su)
or replace (i.e., zdump) the environment after a call to setenv(), putenv() or unsetenv() has been made, a few changes were made. - getenv() will return the value from the new environ array. - setenv() was split into two functions: __setenv() which is most of the previous setenv() without checks on the name and setenv() which contains the checks before calling __setenv(). - setenv(), putenv() and unsetenv() will unset all previous values and call __setenv() on all entries in the new environ array which in turn adds them to the end of the envVars array. Calling __setenv() instead of setenv() is done to avoid the temporary replacement of the '=' in a string with a NUL byte. Some strings may be read-only data. Added more regression checks for clearing the environment array. Replaced gettimeofday() with getrusage() in timing regression check for better accuracy. Fixed an off-by-one bug in __remove_putenv() in the use of memmove(). This went unnoticed due to the allocation of double the number of environ entries when building envVars. Fixed a few spelling mistakes in the comments. Reviewed by: ache Approved by: wes Approved by: re (kensmith)
-rw-r--r--lib/libc/stdlib/getenv.c241
-rw-r--r--tools/regression/environ/envctl.c26
-rw-r--r--tools/regression/environ/envtest.t21
-rw-r--r--tools/regression/environ/timings.c57
4 files changed, 233 insertions, 112 deletions
diff --git a/lib/libc/stdlib/getenv.c b/lib/libc/stdlib/getenv.c
index 5f6f497..b6f6121 100644
--- a/lib/libc/stdlib/getenv.c
+++ b/lib/libc/stdlib/getenv.c
@@ -36,6 +36,12 @@
__FBSDID("$FreeBSD$");
+static const char CorruptEnvFindMsg[] =
+ "environment corrupt; unable to find %.*s";
+static const char CorruptEnvValueMsg[] =
+ "environment corrupt; missing value for %s";
+
+
/*
* Standard environ. environ variable is exposed to entire process.
*
@@ -43,9 +49,12 @@ __FBSDID("$FreeBSD$");
* allows environ to return to as it was before.
* environSize: Number of variables environ can hold. Can only
* increase.
+ * intEnviron: Internally-built environ. Exposed via environ during
+ * (re)builds of the environment.
*/
extern char **environ;
static char **origEnviron;
+static char **intEnviron = NULL;
static int environSize = 0;
/*
@@ -84,7 +93,7 @@ static int envVarsTotal = 0;
/* Deinitialization of new environment. */
-static void __attribute__ ((destructor)) __clean_env(void);
+static void __attribute__ ((destructor)) __clean_env_destructor(void);
/*
@@ -173,6 +182,64 @@ __findenv_environ(const char *name, size_t nameLen)
/*
+ * Remove variable added by putenv() from variable tracking array.
+ */
+static void
+__remove_putenv(int envNdx)
+{
+ envVarsTotal--;
+ if (envVarsTotal > envNdx)
+ memmove(&(envVars[envNdx]), &(envVars[envNdx + 1]),
+ (envVarsTotal - envNdx) * sizeof (*envVars));
+ memset(&(envVars[envVarsTotal]), 0, sizeof (*envVars));
+
+ return;
+}
+
+
+/*
+ * Deallocate the environment built from environ as well as environ then set
+ * both to NULL. Eases debugging of memory leaks.
+ */
+static void
+__clean_env(bool freeVars)
+{
+ int envNdx;
+
+ /* Deallocate environment and environ if created by *env(). */
+ if (envVars != NULL) {
+ for (envNdx = envVarsTotal - 1; envNdx >= 0; envNdx--)
+ /* Free variables or deactivate them. */
+ if (envVars[envNdx].putenv) {
+ if (!freeVars)
+ __remove_putenv(envNdx);
+ } else {
+ if (freeVars)
+ free(envVars[envNdx].name);
+ else
+ envVars[envNdx].active = false;
+ }
+ if (freeVars) {
+ free(envVars);
+ envVars = NULL;
+ } else
+ envActive = 0;
+
+ /* Restore original environ if it has not updated by program. */
+ if (origEnviron != NULL) {
+ if (environ == intEnviron)
+ environ = origEnviron;
+ free(intEnviron);
+ intEnviron = NULL;
+ environSize = 0;
+ }
+ }
+
+ return;
+}
+
+
+/*
* Using the environment, rebuild the environ array for use by other C library
* calls that depend upon it.
*/
@@ -187,20 +254,23 @@ __rebuild_environ(int newEnvironSize)
/* Resize environ. */
if (newEnvironSize > environSize) {
tmpEnvironSize = newEnvironSize * 2;
- tmpEnviron = realloc(environ, sizeof (*environ) *
+ tmpEnviron = realloc(intEnviron, sizeof (*intEnviron) *
(tmpEnvironSize + 1));
if (tmpEnviron == NULL)
return (-1);
environSize = tmpEnvironSize;
- environ = tmpEnviron;
+ intEnviron = tmpEnviron;
}
envActive = newEnvironSize;
/* Assign active variables to environ. */
for (envNdx = envVarsTotal - 1, environNdx = 0; envNdx >= 0; envNdx--)
if (envVars[envNdx].active)
- environ[environNdx++] = envVars[envNdx].name;
- environ[environNdx] = NULL;
+ intEnviron[environNdx++] = envVars[envNdx].name;
+ intEnviron[environNdx] = NULL;
+
+ /* Always set environ which may have been replaced by program. */
+ environ = intEnviron;
return (0);
}
@@ -241,15 +311,12 @@ __build_env(void)
char **env;
int activeNdx;
int envNdx;
- int rtrnVal;
int savedErrno;
size_t nameLen;
/* Check for non-existant environment. */
- if (environ == NULL)
+ if (environ == NULL || environ[0] == NULL)
return (0);
- if (environ[0] == NULL)
- goto SaveEnviron;
/* Count environment variables. */
for (env = environ, envVarsTotal = 0; *env != NULL; env++)
@@ -274,8 +341,7 @@ __build_env(void)
envVars[envNdx].valueSize =
strlen(envVars[envNdx].value);
} else {
- warnx("environment corrupt; missing value for %s",
- envVars[envNdx].name);
+ warnx(CorruptEnvValueMsg, envVars[envNdx].name);
errno = EFAULT;
goto Failure;
}
@@ -290,8 +356,7 @@ __build_env(void)
activeNdx = envVarsTotal - 1;
if (__findenv(envVars[envNdx].name, nameLen, &activeNdx,
false) == NULL) {
- warnx("environment corrupt; unable to find %.*s",
- nameLen, envVars[envNdx].name);
+ warnx(CorruptEnvFindMsg, nameLen, envVars[envNdx].name);
errno = EFAULT;
goto Failure;
}
@@ -299,24 +364,14 @@ __build_env(void)
}
/* Create a new environ. */
-SaveEnviron:
origEnviron = environ;
environ = NULL;
- if (envVarsTotal > 0) {
- rtrnVal = __rebuild_environ(envVarsTotal);
- if (rtrnVal == -1) {
- savedErrno = errno;
- __clean_env();
- errno = savedErrno;
- }
- } else
- rtrnVal = 0;
-
- return (rtrnVal);
+ if (__rebuild_environ(envVarsTotal) == 0)
+ return (0);
Failure:
savedErrno = errno;
- __clean_env();
+ __clean_env(true);
errno = savedErrno;
return (-1);
@@ -324,42 +379,12 @@ Failure:
/*
- * Remove variable added by putenv() from variable tracking array.
+ * Destructor function with default argument to __clean_env().
*/
static void
-__remove_putenv(int envNdx)
+__clean_env_destructor(void)
{
- memmove(&(envVars[envNdx]), &(envVars[envNdx + 1]),
- (envVarsTotal - envNdx) * sizeof (*envVars));
- envVarsTotal--;
-
- return;
-}
-
-
-/*
- * Deallocate the environment built from environ as well as environ then set
- * both to NULL. Eases debugging of memory leaks.
- */
-static void
-__clean_env(void)
-{
- int envNdx;
-
- /* Deallocate environment and environ if created by *env(). */
- if (envVars != NULL) {
- for (envNdx = 0; envNdx < envVarsTotal; envNdx++)
- if (!envVars[envNdx].putenv)
- free(envVars[envNdx].name);
- free(envVars);
- envVars = NULL;
-
- /* Restore original environ. */
- if (origEnviron != NULL) {
- free(environ);
- environ = origEnviron;
- }
- }
+ __clean_env(true);
return;
}
@@ -380,8 +405,12 @@ getenv(const char *name)
return (NULL);
}
- /* Find environment variable via environ or rebuilt environment. */
- if (envVars == NULL)
+ /*
+ * Find environment variable via environ if no changes have been made
+ * via a *env() call or environ has been replaced by a running program,
+ * otherwise, use the rebuilt environment.
+ */
+ if (envVars == NULL || environ != intEnviron)
return (__findenv_environ(name, nameLen));
else {
envNdx = envVarsTotal - 1;
@@ -395,27 +424,19 @@ getenv(const char *name)
* older setting has enough room to store the new value, it will be reused. No
* previous variables are ever freed here to avoid causing a segmentation fault
* in a user's code.
+ *
+ * The variables nameLen and valueLen are passed into here to allow the caller
+ * to calculate the length by means besides just strlen().
*/
-int
-setenv(const char *name, const char *value, int overwrite)
+static int
+__setenv(const char *name, size_t nameLen, const char *value, int overwrite)
{
bool reuse;
char *env;
int envNdx;
int newEnvActive;
- size_t nameLen;
size_t valueLen;
- /* Check for malformed name. */
- if (name == NULL || (nameLen = __strleneq(name)) == 0) {
- errno = EINVAL;
- return (-1);
- }
-
- /* Initialize environment. */
- if (envVars == NULL && __build_env() == -1)
- return (-1);
-
/* Find existing environment variable large enough to use. */
envNdx = envVarsTotal - 1;
newEnvActive = envActive;
@@ -437,7 +458,6 @@ setenv(const char *name, const char *value, int overwrite)
/* Entry is large enough to reuse. */
else if (envVars[envNdx].valueSize >= valueLen)
reuse = true;
-
}
/* Create new variable if none was found of sufficient size. */
@@ -480,7 +500,72 @@ setenv(const char *name, const char *value, int overwrite)
/*
- * Insert a "name=value" string into then environment. Special settings must be
+ * If the program attempts to replace the array of environment variables
+ * (environ) environ, then deactivate all variables and merge in the new list
+ * from environ.
+ */
+static int
+__merge_environ(void)
+{
+ char **env;
+ char *equals;
+
+ /* environ has been replaced. clean up everything. */
+ if (envVarsTotal > 0 && environ != intEnviron) {
+ /* Deactivate all environment variables. */
+ if (envActive > 0) {
+ origEnviron = NULL;
+ __clean_env(false);
+ }
+
+ /*
+ * Insert new environ into existing, yet deactivated,
+ * environment array.
+ */
+ origEnviron = environ;
+ if (origEnviron != NULL)
+ for (env = origEnviron; *env != NULL; env++) {
+ if ((equals = strchr(*env, '=')) == NULL) {
+ warnx(CorruptEnvValueMsg, *env);
+ errno = EFAULT;
+ return (-1);
+ }
+ if (__setenv(*env, equals - *env, equals + 1,
+ 1) == -1)
+ return (-1);
+ }
+ }
+
+ return (0);
+}
+
+
+/*
+ * The exposed setenv() that peforms a few tests before calling the function
+ * (__setenv()) that does the actual work of inserting a variable into the
+ * environment.
+ */
+int
+setenv(const char *name, const char *value, int overwrite)
+{
+ size_t nameLen;
+
+ /* Check for malformed name. */
+ if (name == NULL || (nameLen = __strleneq(name)) == 0) {
+ errno = EINVAL;
+ return (-1);
+ }
+
+ /* Initialize environment. */
+ if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
+ return (-1);
+
+ return (__setenv(name, nameLen, value, overwrite));
+}
+
+
+/*
+ * Insert a "name=value" string into the environment. Special settings must be
* made to keep setenv() from reusing this memory block and unsetenv() from
* allowing it to be tracked.
*/
@@ -500,7 +585,7 @@ putenv(char *string)
}
/* Initialize environment. */
- if (envVars == NULL && __build_env() == -1)
+ if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
return (-1);
/* Deactivate previous environment variable. */
@@ -552,7 +637,7 @@ unsetenv(const char *name)
}
/* Initialize environment. */
- if (envVars == NULL && __build_env() == -1)
+ if (__merge_environ() == -1 || (envVars == NULL && __build_env() == -1))
return (-1);
/* Deactivate specified variable. */
diff --git a/tools/regression/environ/envctl.c b/tools/regression/environ/envctl.c
index 2681741..e077e42 100644
--- a/tools/regression/environ/envctl.c
+++ b/tools/regression/environ/envctl.c
@@ -54,17 +54,19 @@ dump_environ(void)
static void
usage(const char *program)
{
- fprintf(stderr, "Usage: %s [-DGUcht] [-gu name] [-p name=value] "
+ fprintf(stderr, "Usage: %s [-CDGUchrt] [-gu name] [-p name=value] "
"[(-S|-s name) value overwrite]\n\n"
"Options:\n"
+ " -C\t\t\t\tClear environ variable with NULL pointer\n"
" -D\t\t\t\tDump environ\n"
" -G name\t\t\tgetenv(NULL)\n"
" -S value overwrite\t\tsetenv(NULL, value, overwrite)\n"
" -U\t\t\t\tunsetenv(NULL)\n"
- " -c\t\t\t\tClear environ variable\n"
+ " -c\t\t\t\tClear environ variable with calloc()'d memory\n"
" -g name\t\t\tgetenv(name)\n"
" -h\t\t\t\tHelp\n"
" -p name=value\t\t\tputenv(name=value)\n"
+ " -r\t\t\t\treplace environ with { \"FOO=bar\", NULL }\n"
" -s name value overwrite\tsetenv(name, value, overwrite)\n"
" -t\t\t\t\tOutput is suitable for testing (no newlines)\n"
" -u name\t\t\tunsetenv(name)\n",
@@ -77,7 +79,7 @@ usage(const char *program)
int
main(int argc, char **argv)
{
- char *cleanEnv[] = { NULL };
+ char *staticEnv[] = { "FOO=bar", NULL };
char arg;
const char *eol = "\n";
const char *value;
@@ -87,15 +89,19 @@ main(int argc, char **argv)
exit(EXIT_FAILURE);
}
- while ((arg = getopt(argc, argv, "DGS:Ucg:hp:s:tu:")) != -1) {
+ while ((arg = getopt(argc, argv, "CDGS:Ucg:hp:rs:tu:")) != -1) {
switch (arg) {
- case 'D':
- errno = 0;
- dump_environ();
+ case 'C':
+ environ = NULL;
break;
case 'c':
- environ = cleanEnv;
+ environ = calloc(1, sizeof(*environ));
+ break;
+
+ case 'D':
+ errno = 0;
+ dump_environ();
break;
case 'G':
@@ -113,6 +119,10 @@ main(int argc, char **argv)
printf("%d %d%s", putenv(optarg), errno, eol);
break;
+ case 'r':
+ environ = staticEnv;
+ break;
+
case 'S':
errno = 0;
printf("%d %d%s", setenv(NULL, optarg,
diff --git a/tools/regression/environ/envtest.t b/tools/regression/environ/envtest.t
index e3aca95..2b2c548 100644
--- a/tools/regression/environ/envtest.t
+++ b/tools/regression/environ/envtest.t
@@ -132,6 +132,9 @@ run_test -s FOO ${NEWBAR} 1 -s FOO ${BAR} 1 -s FOO ${NEWBAR} 1 -s FOO ${BAR} 1\
-g FOO
check_result "0 0 0 0 0 0 0 0 ${BAR}"
+run_test -c -s FOO ${BAR} 1 -g FOO -c -s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
# Unsets.
run_test -u FOO -g FOO
@@ -152,6 +155,10 @@ check_result "-1 22"
run_test -c -s FOO ${NEWBAR} 1 -g FOO -u FOO -g FOO
check_result "0 0 ${NEWBAR} 0 0"
+run_test -c -u FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO -c -u FOO\
+ -s FOO ${NEWBAR} 1 -g FOO
+check_result "0 0 0 0 ${BAR} 0 0 0 0 0 0 ${NEWBAR}"
+
# Puts.
run_test -p FOO=${NEWBAR} -g FOO
@@ -180,3 +187,17 @@ check_result "0 0 0 0 0 0"
run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -u FOO
check_result "0 0 0 0 0 0"
+
+run_test -s FOO ${NEWBAR} 1 -p FOO=${BAR} -c -g FOO -p FOO=${NEWBAR} -g FOO
+check_result "0 0 0 0 0 0 ${NEWBAR}"
+
+run_test -c -p FOO=${BAR} -g FOO -c -p FOO=${NEWBAR} -g FOO
+check_result "0 0 ${BAR} 0 0 ${NEWBAR}"
+
+
+# environ replacements.
+run_test -r -g FOO -s FOO ${BAR} 1 -g FOO -u FOO -g FOO
+check_result "${BAR} 0 0 ${BAR} 0 0"
+
+run_test -r -g FOO -u FOO -g FOO -s FOO ${BAR} 1 -g FOO
+check_result "${BAR} 0 0 0 0 ${BAR}"
diff --git a/tools/regression/environ/timings.c b/tools/regression/environ/timings.c
index 1bf3c91..7999fa1 100644
--- a/tools/regression/environ/timings.c
+++ b/tools/regression/environ/timings.c
@@ -23,7 +23,9 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
+#include <sys/types.h>
#include <sys/time.h>
+#include <sys/resource.h>
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
@@ -64,43 +66,44 @@ int
main(int argc, char **argv)
{
int iterations;
- struct timeval endTime;
- struct timeval startTime;
+ struct rusage endUsage;
+ struct rusage startUsage;
/*
* getenv() on the existing environment.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
if (getenv(name) == NULL)
err(EXIT_FAILURE, "getenv(name)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("getenv(name)", &startTime, &endTime);
+ report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
/*
* setenv() a variable with a large value.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
if (setenv(name, value1, 1) == -1)
err(EXIT_FAILURE, "setenv(name, value1, 1)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("setenv(name, value1, 1)", &startTime, &endTime);
+ report_time("setenv(name, value1, 1)", &startUsage.ru_utime,
+ &endUsage.ru_utime);
/*
* getenv() the new variable on the new environment.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -108,15 +111,15 @@ main(int argc, char **argv)
if (getenv(name) == NULL)
err(EXIT_FAILURE, "getenv(name)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("getenv(name)", &startTime, &endTime);
+ report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
/*
* getenv() a different variable on the new environment.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -124,30 +127,31 @@ main(int argc, char **argv)
if (getenv(name2) == NULL)
err(EXIT_FAILURE, "getenv(name2)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("getenv(name2)", &startTime, &endTime);
+ report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
/*
* setenv() a variable with a small value.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
if (setenv(name, value2, 1) == -1)
err(EXIT_FAILURE, "setenv(name, value2, 1)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("setenv(name, value2, 1)", &startTime, &endTime);
+ report_time("setenv(name, value2, 1)", &startUsage.ru_utime,
+ &endUsage.ru_utime);
/*
* getenv() a different variable on the new environment.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -155,15 +159,15 @@ main(int argc, char **argv)
if (getenv(name2) == NULL)
err(EXIT_FAILURE, "getenv(name)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("getenv(name)", &startTime, &endTime);
+ report_time("getenv(name)", &startUsage.ru_utime, &endUsage.ru_utime);
/*
* getenv() a different variable on the new environment.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
@@ -171,24 +175,25 @@ main(int argc, char **argv)
if (getenv(name2) == NULL)
err(EXIT_FAILURE, "getenv(name2)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("getenv(name2)", &startTime, &endTime);
+ report_time("getenv(name2)", &startUsage.ru_utime, &endUsage.ru_utime);
/*
* putenv() a variable with a small value.
*/
- gettimeofday(&startTime, NULL);
+ getrusage(RUSAGE_SELF, &startUsage);
/* Iterate over setting variable. */
for (iterations = 0; iterations < MaxIterations; iterations++)
if (putenv(nameValuePair) == -1)
err(EXIT_FAILURE, "putenv(nameValuePair)");
- gettimeofday(&endTime, NULL);
+ getrusage(RUSAGE_SELF, &endUsage);
- report_time("putenv(nameValuePair)", &startTime, &endTime);
+ report_time("putenv(nameValuePair)", &startUsage.ru_utime,
+ &endUsage.ru_utime);
exit(EXIT_SUCCESS);
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